Do Gleason patterns 3 and 4 prostate cancer represent separate disease states?

Graph-based multi-modality integration for prediction of cancer subtype and severity

Personalised cancer screening before therapy paves the way toward improving diagnostic accuracy and treatment outcomes. Most approaches are limited to a single data type and do not consider interactions between features, leaving aside the complementary insights that multimodality and systems biology can provide. In this project, we demonstrate the use of graph theory for data integration via individual networks where nodes and edges are individual-specific. We showcase the consequences of early, intermediate, and late graph-based fusion of RNA-Seq data and histopathology whole-slide images for predicting cancer subtypes and severity. The methodology developed is as follows: (1) we create individual networks; (2) we compute the similarity between individuals from these graphs; (3) we train our model on the similarity matrices; (4) we evaluate the performance using the macro F1 score. Pros and cons of elements of the pipeline are evaluated on publicly available real-life datasets. We find that graph-based methods can increase performance over methods that do not study interactions. Additionally, merging multiple data sources often improves classification compared to models based on single data, especially through intermediate fusion. The proposed workflow can easily be adapted to other disease contexts to accelerate and enhance personalized healthcare.

The Transcriptomic Profiles of ESR1 and MMP3 Stratify the Risk of Biochemical Recurrence in Primary Prostate Cancer beyond Clinical Features

The molecular determinants of the heterogenic course of prostate cancer (PC) remain elusive. We aimed to determine the drivers predisposing to unfavorable PC outcomes anticipated by BCR events among patients of similar preoperative characteristics. The TCGA transcriptomic and clinical data of 497 PC individuals were used, stratified according to the risk of BCR by EAU-EANM-ESTRO-ESUR-SIOG. The relevance of the functional markers regarding BCR-free survival was examined by the cutp algorithm. Through UpSetR, subgroups of PC patients bearing an unfavorable signature were identified, followed by the hierarchical clustering of the major markers of the epithelial-to-mesenchymal transition (EMT). BCR-free survival was estimated with the Cox proportional hazards regression model. ESR1 significantly differentiated BCR-free survival, whereas AR did not. An elevation in KLK3 correlated with better prognosis, although PGR, KLK3, CDH1, and MMP3 predicted BCR better than the preoperative PSA level. Patients sharing an unfavorable profile of ESR1 and MMP3 together with lymph node status, Gleason score, T, and EAU risk groups were at a higher risk of BCR originating from mesenchymal features of PC cells. To conclude, we revealed an ESR1-driven unfavorable profile of EMT underpinning a worse PC trajectory. ESR1 may have a major role in PC progression; therefore, it could become a major focus for further investigations.

Blood Prostate-specific Antigen by Volume of Benign, Gleason Pattern 3 and 4 Prostate Tissue

OBJECTIVE

To evaluate how blood levels of prostate-specific antigen (PSA) relate to prostate volume of benign tissue, Gleason pattern 3 (GP3) and Gleason pattern 4 (GP4) cancer.

METHODS

The cohort included 2209 consecutive men undergoing radical prostatectomy at 2 academic institutions with pT2N0, Grade Group 1-4 prostate cancer and an undetectable postoperative PSA. Volume of benign, GP3, and GP4 were estimated. The primary analysis evaluated the association between PSA and volume of each type of tissue using multivariable linear regression. R2, a measure of explained variation, was calculated using a multivariable model.

RESULTS

Estimated contribution to PSA was 0.04/0.06 ng/mL/cc for benign, 0.08/0.14 ng/mL/cc for GP3, and 0.62/0.80 ng/ml/cc for GP4 for the 2 independent cohorts, respectively. GP4 was associated with 6 to 8-fold more PSA per cc compared to GP3 and 15-fold higher compared to benign tissue. We did not observe a difference between PSA per cc for GP3 vs. benign tissue (P = 0.2). R2 decreased only slightly when removing age (0.006/0.018), volume of benign tissue (0.051/0.054) or GP3 (0.014/0.023) from the model. When GP4 was removed, R2 decreased 0.051/0.310. PSA density (PSA divided by prostate volume) was associated with volume of GP4 but not GP3, after adjustment for benign volume.

CONCLUSION

Gleason pattern 4 cancer contributes considerably more to PSA and PSA density per unit volume compared to GP3 and benign tissue. Contributions from GP3 and benign are similar. Further research should examine the utility of determining clinical management recommendations by absolute volume of GP4 rather than the ratio of GP3 to GP4.

Novel serum proteomic biomarkers for early diagnosis and aggressive grade identification of prostate cancer

BACKGROUND

Prostate cancer (PCa) is one of the most common tumors and the second leading cause of cancer-related death in men. The discovery of novel biomarkers for PCa diagnosis in the early stage, as well as discriminating aggressive PCa from non-aggressive PCa continue to pose a challenge. The aim of this study was to identify serum proteins that were sensitive and specific enough to detect early-stage and aggressive PCa.

METHODS

The serum proteomic profiling of patients with PCa and benign prostatic hyperplasia (BPH) was comprehensively analyzed using data-independent acquisition mass spectrometry (DIA-MS), and the bioinformatics analysis was performed. The differentially expressed proteins (DEPs) of interest were further verified by enzyme-linked immunosorbent assay (ELISA) and immunoturbidimetry assay.

RESULTS

Statistically significant difference in abundance showed 56 DEPs between early-stage PCa and BPH and 47 DEPs between aggressive and non-aggressive PCa patients. In addition, the verification results showed that serum L-selectin concentration was significantly higher (p<0.05) in Gleason 6 PCa when compared with BPH, and the concentration of osteopontin (SPP1) and ceruloplasmin (CP) increased with higher Gleason score.

CONCLUSIONS

DIA-MS has great potential in cancer-related biomarker screening. Our data demonstrated that adding SPP1 and CP to PSA improved the separation of Gleason 7 (4 + 3) or above from Gleason 7 (3 + 4) or below compared with PSA diagnosis alone. Serum SPP1 and CP could be effective biomarkers to differentiate aggressive PCa (especially Gleason 7 (4 + 3) or above) from non-aggressive disease.

A transcriptomic signature for prostate cancer relapse prediction identified from the differentially expressed genes between TP53 mutant and wild-type tumors

For prostate cancer (PCa) patients, biochemical recurrence (BCR) is the first sign of disease relapse and the subsequent metastasis. TP53 mutations are relatively prevalent in advanced PCa forms. We aimed to utilize this knowledge to identify robust transcriptomic signatures for BCR prediction in patients with Gleason score ≥ 7 cancers, which cause most PCa deaths. Using the TCGA-PRAD dataset and the novel data-driven stochastic approach proposed in this study, we identified a 25-gene signature from the genes whose expression in tumors was associated with TP53 mutation statuses. The predictive strength of the signature was assessed by AUC and Fisher’s exact test p-value according to the output of support vector machine-based cross validation. For the TCGA-PRAD dataset, the AUC and p-value were 0.837 and 5 × 10^–13, respectively. For five external datasets, the AUCs and p-values ranged from 0.632 to 0.794 and 6 × 10^–2 to 5 × 10^–5, respectively. The signature also performed well in predicting relapse-free survival (RFS). The signature-based transcriptomic risk scores (TRS) explained 28.2% of variation in RFS on average. The combination of TRS and clinicopathologic prognostic factors explained 23–72% of variation in RFS, with a median of 54.5%. Our method and findings are useful for developing new prognostic tools in PCa and other cancers.

Deciphering the Increased Prevalence of TP53 Mutations in Metastatic Prostate Cancer

The prevalence of TP53 mutations in advanced prostate cancers (PCa) is 3 to 5 times of the quantity in primary PCa. By an integrative analysis of the Cancer Genome Atlas and Catalogue of Somatic Mutations in Cancer data, we revealed the supporting evidence for 2 complementary hypotheses: H₁ - TP53 abnormalities promote metastasis or therapy-resistance of PCa cells, and H₂—part of TP53 mutations in PCa metastases occur after the diagnosis of original cancers. The plausibility of these hypotheses can explain the increased prevalence of TP53 mutations in PCa metastases. With H₁ and H₂ as the general assumptions, we developed mathematical models to decipher the change of the percentage frequency (prevalence) of TP53 mutations from primary tumors to metastases. The following results were obtained. Compared to TP53-normal patients, TP53-mutated patients had poorer biochemical relapse-free survival, higher Gleason scores, and more advanced t-stages (P < .01). Single-nucleotide variants in metastases more frequently occurred on G bases of the coding sequence than those in primary cancers (P = .03). The profile of TP53 hotspot mutations was significantly different between primary and metastatic PCa as demonstrated in a set of statistical tests (P < .05). By the derived formulae, we estimated that about 40% TP53 mutation records collected from metastases occurred after the diagnosis of the original cancers. Our study provided significant insight into PCa progression. The proposed models can also be applied to decipher the prevalence of mutations on TP53 (or other driver genes) in other cancer types.

Prostate Cancer Disparities in Risk Group at Presentation and Access to Treatment for Asian Americans, Native Hawaiians, and Pacific Islanders: A Study With Disaggregated Ethnic Groups

PURPOSE

We identified (1) differences in localized prostate cancer (PCa) risk group at presentation and (2) disparities in access to initial treatment for Asian American, Native Hawaiian, and Pacific Islander (AANHPI) men with PCa after controlling for sociodemographic factors.

METHODS

We assessed all patients in the National Cancer Database with localized PCa with low-, intermediate-, and high-risk disease who identified as Thai, White, Asian Indian, Chinese, Vietnamese, Korean, Japanese, Filipino, Hawaiian, Pacific Islander, Laotian, Pakistani, Kampuchean, and Hmong. Multivariable logistic regression defined adjusted odds ratios (AORs) with 95% CI of (1) presenting at progressively higher risk group and (2) receiving treatment or active surveillance with intermediate- or high-risk disease, adjusting for sociodemographic and clinical factors.

RESULTS

Among 980,889 men (median age 66 years), all AANHPI subgroups with the exception of Thai (AOR = 0.84 [95% CI, 0.58 to 1.21], P > .05), Asian Indian (AOR = 1.12 [95% CI, 1.00 to 1.25], P > .05), and Pakistani (AOR = 1.34 [95% CI, 0.98 to 1.83], P > .05) men had greater odds of presenting at a progressively higher PCa risk group compared with White patients (Chinese AOR = 1.18 [95% CI, 1.11 to 1.25], P < .001; Japanese AOR = 1.36 [95% CI, 1.26 to 1.47], P < .001; Filipino AOR = 1.37 [95% CI, 1.29 to 1.46], P < .001; Korean AOR = 1.32 [95% CI, 1.18 to 1.48], P < .001; Vietnamese AOR = 1.20 [95% CI, 1.07 to 1.35], P = .002; Laotian AOR = 1.60 [95% CI, 1.08 to 2.36], P = .018; Hmong AOR = 4.07 [95% CI, 1.54 to 10.81], P = .005; Kampuchean AOR = 1.55 [95% CI, 1.03 to 2.34], P = .036; Asian Indian or Pakistani AOR = 1.15 [95% CI, 1.07 to 1.24], P < .001; Native Hawaiians AOR = 1.58 [95% CI, 1.38 to 1.80], P < .001; and Pacific Islanders AOR = 1.58 [95% CI, 1.37 to 1.82], P < .001). Additionally, Japanese Americans (AOR = 1.46 [95% CI, 1.09 to 1.97], P = .013) were more likely to receive treatment compared with White patients.

CONCLUSION

Our findings suggest that there are differences in PCa risk group at presentation by race or ethnicity among Asian American, Native Hawaiian, and Pacific Islander subgroups and that there exist disparities in treatment patterns. Although AANHPI are often studied as a homogenous group, heterogeneity upon subgroup disaggregation underscores the importance of further study to assess and address barriers to PCa care.

Defining prostate cancer size and treatment margin for focal therapy: does intralesional heterogeneity impact the performance of multiparametric MRI?

OBJECTIVES

To evaluate the impact of intralesional heterogeneity on the performance of multiparametric magnetic resonance imaging (mpMRI) in determining cancer extent and treatment margins for focal therapy (FT) of prostate cancer.

PATIENTS AND METHODS

We identified men who underwent primary radical prostatectomy for organ- confined prostate cancer over a 3-year period. Cancer foci on whole-mount histology were marked out, coding low-grade (LG; Gleason 3) and high-grade (HG; Gleason 4-5) components separately. Measurements of entire tumours were grouped according to intralesional proportion of HG cancer: 0%, <50% and ≥50%; the readings were corrected for specimen shrinkage and correlated with matching lesions on mpMRI. Separate measurements were also taken of HG cancer components only, and correlated against entire lesions on mpMRI. Size discrepancies were used to derive the optimal tumour size and treatment margins for FT.

RESULTS

There were 122 MRI-detected cancer lesions in 70 men. The mean linear specimen shrinkage was 8.4%. The overall correlation between histology and MRI dimensions was r = 0.79 (P < 0.001). Size correlation was superior for tumours with high burden (≥50%) compared to low burden (<50%) of HG cancer (r = 0.84 vs r = 0.63; P = 0.007). Size underestimation by mpMRI was more likely for larger tumours (51% for >12 mm vs 26% for ≤12 mm) and those containing HG cancer (44%, vs 20% for LG only). Size discrepancy analysis suggests an optimal tumour size of ≤12 mm and treatment margins of 5-6 mm for FT. For tumours ≤12 mm in diameter, applying 5- and 6-mm treatment margins would achieve 98.6% and 100% complete tumour ablation, respectively. For tumours of all sizes, using the same margins would ablate >95% of the HG cancer components.

CONCLUSIONS

Multiparametric MRI performance in estimating prostate cancer size, and consequently the treatment margin for FT, is impacted by tumour size and the intralesional heterogeneity of cancer grades.

PSA density in the diagnosis of prostate cancer in the Chinese population: results from the Chinese Prostate Cancer Consortium

We performed this study to investigate the diagnostic performance of prostate-specific antigen density (PSAD) in a multicenter cohort of the Chinese Prostate Cancer Consortium. Outpatients with prostate-specific antigen (PSA) levels ≥4.0 ng ml⁻¹ regardless of digital rectal examination (DRE) results or PSA levels <4.0 ng ml⁻¹ and abnormal DRE results were included from 18 large referral hospitals in China. The diagnostic performance of PSAD and the sensitivity and specificity for the diagnosis of prostate cancer (PCa) and high-grade prostate cancer (HGPCa) at different cutoff values were evaluated. A total of 5220 patients were included in the study, and 2014 (38.6%) of them were diagnosed with PCa. In patients with PSA levels ranging from 4.0 to 10.0 ng ml⁻¹, PSAD was associated with PCa and HGPCa in both univariate (odds ratio [OR] = 45.15, P < 0.0001 and OR = 25.38, P < 0.0001, respectively) and multivariate analyses (OR = 52.55, P < 0.0001 and OR = 26.05, P < 0.0001, respectively). The areas under the receiver operating characteristic curves (AUCs) of PSAD in predicting PCa and HGPCa were 0.627 and 0.630, respectively. With the PSAD cutoff of 0.10 ng ml⁻², we obtained a sensitivity of 88.7% for PCa, and nearly all (89.9%) HGPCa cases could be detected and biopsies could be avoided in 20.2% of the patients (359/1776 cases). Among these patients who avoided biopsies, only 30 cases had HGPCa. We recommend 0.10 ng ml⁻² as the proper cutoff value of PSAD, which will obtain a sensitivity of nearly 90% for both PCa and HGPCa. The results of this study should be validated in prospective, population-based multicenter studies.

Differences in survival of prostate cancer Gleason 8-10 disease and the establishment of a new Gleason survival grading system

Background

Although the latest Gleason grading system in 2014 has distinguished between Gleason 3 + 4 and 4 + 3, Gleason 8 and Gleason 9–10 are remained systemically classified.

Methods

A total of 261,125 patients diagnosed with prostate cancer (PCa) were selected between 2005 and 2015 from the Surveillance, Epidemiology, and End Results (SEER) database. We used propensity score matching to balance clinical variables and then compared overall survival (OS) and cancer‐specific survival (CSS) between Gleason score subgroups. We further establish a new Gleason survival grading system based on the hazard ratio (HR) values of each Gleason subgroup. Cox proportional hazards models and Kaplan–Meier curves were used to compare patient survival.

Results

Among PCa patients with Gleason score 8 disease, patients with Gleason 5 + 3 had significantly worse OS and CSS than those with Gleason 3 + 5 (OS: HR = 1.26, p = 0.042; CSS: HR = 1.42, p = 0.005) and 4 + 4 (HR = 1.50 for OS and HR = 1.69 for CSS, p < 0.001 for all). PCa patients with Gleason 5 + 3 and Gleason 4 + 5 may have the similar OS and CSS (reference Gleason score <=6, 5 + 3: OS HR = 2.44, CSS HR = 7.63; 4 + 5: OS HR = 2.40, CSS HR = 8.92; p < 0.001 for all). The new Gleason survival grading system reclassified the grades 4 and 5 of the 2014 updated Gleason grading system into three hierarchical grades, which makes the classification of grades more detailed and accurate.

Conclusion

PCa patients with Gleason 8–10 may have three different survival subgroups, Gleason 3 + 5 and 4 + 4, Gleason 5 + 3 and 4 + 5, and Gleason 5 + 4 and 5 + 5. Our results maximize risk stratification for PCa patients, provide guidance for clinicians to assess their survival and clinical management, and make a recommendation for the next Gleason grading system update.

Gene expression analysis reveals a pitfall in the molecular research of prostate tumors relevant to Gleason score

Gleason score (GS) is a powerful prognostic factor in prostate cancer (PCa). A GS-7 tumor typically has the primary Gleason (architectural) pattern and secondary prevalent one being graded with 3 and 4 (or 4 and 3), respectively. Due to the well-known intratumoral multifocal occurrence of different patterns, a biological sample from a GS-7 tumor used in a molecular experiment will be uncertain regarding the actually represented pattern if no special attention is given to specimen preparation. In this study, by an integrative analysis of several published gene expression datasets, one of which is the profiling of the paired GP-3 (Gleason pattern 3) and GP-4 (Gleason pattern 4) specimens of 13 GS-7 tumors, we demonstrate that such an uncertainty can be frequently observed in the published data. More specifically, our results suggest that the GS-7 specimens used to generate the frequently-cited The Cancer Genome Atlas (TCGA) data and the Gene Expression Omnibus (GEO) dataset GSE21032 which largely are individual GP-3 or GP-4 specimens rather than the "intermediate" specimens of GP-3 and GP-4. This indicates a pitfall in the existing molecular research of prostate tumors relevant to GS and in GS-related molecular biomarker identification using the previously documented data.

SEER and Gene Expression Data Analysis Deciphers Racial Disparity Patterns in Prostate Cancer Mortality and the Public Health Implication

A major racial disparity in prostate cancer (PCa) is that African American (AA) patients have a higher mortality rate than European American (EA) patients. We filtered the SEER 2009-2011 records and divided them into four groups regarding patient races and cancer grades. On such a partition, we performed a series of statistical analyses to further clarify the aforementioned disparity. Molecular evidence for a primary result of the epidemiological analysis was obtained from gene expression data. The results include: (1) Based on the registry-specific measures, a significant linear regression of total mortality rate (as well as PCa specific mortality rate) on the percentage of (Gleason pattern-based) high-grade cancers (PHG) is demonstrated in EAs (p < 0.01) but not in AAs; (2) PHG and its racial disparity are differentiated across ages and the groups defined by patient outcomes; (3) For patients with cancers in the same grade category, i.e. the high or low grade, the survival stratification between races is not significant in most geographical areas; and (4) The genes differentially expressed between AAs' and EAs' tumors of the same grade category are relatively rare. The perception that prostate tumors are more lethal in AAs than in EAs is reasonable regarding AAs' higher PHG, while high grade alone could not imply aggressiveness. However, this perception is questionable when the comparison is focused on cases within the same grade category. Supporting observations for this conclusion hold a remarkable implication for erasing racial disparity in PCa. That is, "Equal grade, equal outcomes" is not only a verifiable hypothesis but also an achievable public health goal.

Transcriptome Analysis Identifies Piwi-Interacting RNAs as Prognostic Markers for Recurrence of Prostate Cancer

Prostate cancer remains the second leading cause of male cancer death, and there is an unmet need for biomarkers to identify patients with such aggressive disease. Piwi-inteacting RNAs (piRNAs) have been classified as transcriptional and posttranscriptional regulators in somatic cells. In this study, we discovered three piRNAs as novel prognostic markers and their association with prostate cancer biochemical recurrence was confirmed in validation data set. To obtain a better understanding of piRNA expression patterns in prostate cancer and to find gene coexpression with piRNAs, we performed weighted gene coexpression network analysis. Target genes of three piRNAs have also been predicted based on base complementarity and expression correlativity. Functional analysis revealed the relationships between target genes and prostate cancer. Our work also identified differential expression of piRNAs between Gleason stage 3 + 4 and 4 + 3 prostate cancer. Overall, this study may explain the roles and demonstrate the potential clinical utility of piRNAs in prostate cancer in a way.

Biopsy Grade Group as a reliable prognostic factor for BCR in Afro-Caribbean men with intermediate- and high-risk prostate cancer

PURPOSE

The Grade Group (GG) classification is recommended by guidelines as a reliable prognostic factor of prostate cancer. However, most studies have been performed on the Caucasian population. Our objective was to validate GG classification as a safe way to classify intermediate- and high-risk patients with African ancestry.

PATIENTS AND METHODS

This was a retrospective study in an Afro-Caribbean population. A total of 1236 patients were included between 2000 and 2015. Patients were stratified according to (GG). Survival analysis was performed using the Kaplan-Meier method, univariate and multivariate analyses using the Cox model.

RESULTS

There was no significant difference at 5 and 10-year BCR-free survival between the intermediate- and high-risk groups, based on the D'Amico classification. There was a highly significant difference in BCR-free survival at 5 (p < 0.0001) and 10 years (p < 0.0001) for patients of GG 1 and 2 vs 3, 4, and 5, respectively. There was no significant difference in 5-year BCR-free survival of patients of GG grades 1 and 2, whether lymph-node dissection was performed or not. There was a significant difference between GG 2 and 3 patients in 5 (p = 0.008) and 10-year BCR-free survival (p = 0.01). High PSA (p < 0.0001), pathological GG ≥ 3 (p < 0.0001), pathological stage pT3 (p < 0.0001) and positive margins (p < 0.0001) were factors for BCR in multivariate analysis.

CONCLUSION

The GG 2015 classification appears to be a better prognostic factor than D'Amico classification for intermediate- and high-risk Afro-Caribbean patients.

Deep transfer learning-based prostate cancer classification using 3 Tesla multi-parametric MRI

PURPOSE

The purpose of the study was to propose a deep transfer learning (DTL)-based model to distinguish indolent from clinically significant prostate cancer (PCa) lesions and to compare the DTL-based model with a deep learning (DL) model without transfer learning and PIRADS v2 score on 3 Tesla multi-parametric MRI (3T mp-MRI) with whole-mount histopathology (WMHP) validation.

METHODS

With IRB approval, 140 patients with 3T mp-MRI and WMHP comprised the study cohort. The DTL-based model was trained on 169 lesions in 110 arbitrarily selected patients and tested on the remaining 47 lesions in 30 patients. We compared the DTL-based model with the same DL model architecture trained from scratch and the classification based on PIRADS v2 score with a threshold of 4 using accuracy, sensitivity, specificity, and area under curve (AUC). Bootstrapping with 2000 resamples was performed to estimate the 95% confidence interval (CI) for AUC.

RESULTS

After training on 169 lesions in 110 patients, the AUC of discriminating indolent from clinically significant PCa lesions of the DTL-based model, DL model without transfer learning and PIRADS v2 score ≥ 4 were 0.726 (CI [0.575, 0.876]), 0.687 (CI [0.532, 0.843]), and 0.711 (CI [0.575, 0.847]), respectively, in the testing set. The DTL-based model achieved higher AUC compared to the DL model without transfer learning and PIRADS v2 score ≥ 4 in discriminating clinically significant lesions in the testing set.

CONCLUSION

The DeLong test indicated that the DTL-based model achieved comparable AUC compared to the classification based on PIRADS v2 score (p = 0.89).

Appraising risk in active surveillance of localized prostate cancer

Objectives

Men diagnosed with low‐risk prostate cancer are typically eligible for active surveillance of their cancer, involving monitoring for cancer progression and making judgements about the risks of prostate cancer against those of active intervention. Our study examined how risk for prostate cancer is perceived and experienced by patients undergoing active surveillance with their clinicians, how risk is communicated in clinical consultations, and the implications for treatment and care.

Method

Participants were nine patients and three clinicians from a university hospital urology clinic. A staged, qualitative, multi‐method data collection approach was undertaken, comprising: observations of consultations; patient and clinician interviews; and patient surveys. The three data sets were analysed separately using thematic analysis and then integrated to give a comprehensive view of patient and clinician views.

Results

Thirty data points (eight patient surveys; 10 observations of consultations between patients and clinicians; 10 patient interviews; and two clinician interviews) combined to create a detailed picture of how patients perceived and appraised risk, in three themes of “Making sense of risk”, “Talking about risk” and “Responding to risk”.

Conclusion

Effective risk communication needs to be finely tuned and timed to individual patient's priorities and information requirements. A structured information exchange process that identifies patients' priorities, and details key moments in risk assessment, so that complexities of risk are discussed in ways that are meaningful to patients, may benefit patient care. These findings could inform the development of patient‐centric risk assessment procedures and service delivery models in prostate cancer care more broadly.

Path R-CNN for Prostate Cancer Diagnosis and Gleason Grading of Histological Images

Prostate cancer is the most common and second most deadly form of cancer in men in the United States. The classification of prostate cancers based on Gleason grading using histological images is important in risk assessment and treatment planning for patients. Here, we demonstrate a new region-based convolutional neural network framework for multi-task prediction using an epithelial network head and a grading network head. Compared with a single-task model, our multi-task model can provide complementary contextual information, which contributes to better performance. Our model is achieved a state-of-the-art performance in epithelial cells detection and Gleason grading tasks simultaneously. Using fivefold cross-validation, our model is achieved an epithelial cells detection accuracy of 99.07% with an average area under the curve of 0.998. As for Gleason grading, our model is obtained a mean intersection over union of 79.56% and an overall pixel accuracy of 89.40%.

An EM-based semi-supervised deep learning approach for semantic segmentation of histopathological images from radical prostatectomies

Automated Gleason grading is an important preliminary step for quantitative histopathological feature extraction. Different from the traditional task of classifying small pre-selected homogeneous regions, semantic segmentation provides pixel-wise Gleason predictions across an entire slide. Deep learning-based segmentation models can automatically learn visual semantics from data, which alleviates the need for feature engineering. However, performance of deep learning models is limited by the scarcity of large-scale fully annotated datasets, which can be both expensive and time-consuming to create. One way to address this problem is to leverage external weakly labeled datasets to augment models trained on the limited data. In this paper, we developed an expectation maximization-based approach constrained by an approximated prior distribution in order to extract useful representations from a large number of weakly labeled images generated from low-magnification annotations. This method was utilized to improve the performance of a model trained on a limited fully annotated dataset. Our semi-supervised approach trained with 135 fully annotated and 1800 weakly annotated tiles achieved a mean Jaccard Index of 49.5% on an independent test set, which was 14% higher than the initial model trained only on the fully annotated dataset.

Medium-term Follow-up of Vascular-targeted Photodynamic Therapy of Localized Prostate Cancer Using TOOKAD Soluble WST-11 (Phase II Trials)

BACKGROUND AND OBJECTIVE

To assess the medium-term tumor control in patients with localized prostate cancer (PCa) treated with vascular-targeted photodynamic (VTP) therapy with TOOKAD Soluble WST11 (VTP) and to assess the medium-term tolerability of the treatment.

DESIGN, SETTING, PARTICIPANTS, AND INTERVENTION

During the clinical phase II studies, 68 patients were treated with VTP under optimal treatment conditions (WST11 at 4mg/kg, light energy at 200J/cm, and a light density index ≥1) and have been included in a 3.5-yr follow-up.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Post-interventional visits were scheduled every 6 mo and conducted as per local standard practice in each study center. Cancer-free status was assessed by means of prostate-specific antigen kinetics, multiparametric magnetic resonance imaging and/or prostate biopsies.

RESULTS AND LIMITATIONS

At the end of the 3.5-yr follow-up, overall successful focal ablation was achieved for 51 patients (75%). Cancer was identified in the untreated lobe in 17 patients (25%). In total, 34 patients (50%) were cancer-free in both the prostate lobes. In case of recurrent/persistent malignancy, the Gleason score remained consistent or changed at the maximum by one point (upgrading by 1 Gleason point to 3+4 for eight patients and 4+3 for two patients). There were 64 related adverse events (AEs): 48% were Clavien grade I, 47% were grade II, and 5% were grade III. There were no Clavien grade IV and V AEs. Limitations included small sample size and heterogeneity in the follow-up for some centers.

CONCLUSIONS

VTP is a safe and efficient treatment and represents an alternative option for localized low-risk PCa management over the medium term. Precise diagnostic methods and imaging tools are thereby essential requirements to ensure safe and complete targeted therapy.

PATIENT SUMMARY

In this report, we looked at the medium-term outcomes of focal photodynamic therapy for early-stage prostate cancer. We found that this form of treatment is efficient and might have the potential to become a therapeutic option for low-risk cancer. Effectiveness depends on precise diagnostic methods, such as magnetic resonance imaging and accurate biopsy.

Clinical and biochemical markers of visceral adipose tissue activity: Body mass index, visceral adiposity index, leptin, adiponectin, and matrix metalloproteinase-3. Correlation with Gleason patterns 4 and 5 at prostate biopsy

Context:

The correlation between aggressive prostate cancer and obesity mainly based on body mass index (BMI) and pathology after surgery remains controversial.

Aims:

The aim of the study was to correlate BMI, visceral adiposity index (VAI), and the plasmatic levels of leptin, adiponectin, and matrix metalloproteinase-3 (MMP-3), and biomarkers of adipose tissue function, with the detection of Gleason patterns 4 and 5 at biopsy.

Subjects and Methods:

Consecutive patients with prostate cancer at 12-core transrectal biopsy were enrolled. BMI, waist circumference (WC), blood samples to evaluate the plasmatic levels of triglycerides (TG) and high-density lipoproteins (HDL), adiponectin, leptin, and MMP-3 were obtained immediately before biopsy. The VAI was calculated according to the formula: WC/(39.68 + [1.88 × BMI]) × TG/1.03 × 1.31/HDL.

Results:

One hundred and forty-nine patients were entered. The median PSA, BMI, and VAI were 10.0 ng/ml, 27.6 kg/m², and 4.6, respectively. Gleason patterns 4 or 5 were detected in 68 (45.6%) patients; in 15 (41.7%), 31 (44.9%), and 22 (50.0%) among normal weight, overweight, and obese patients, respectively (P = 0.55). The statistical analysis did not show any significant correlation between BMI, VAI, the plasmatic levels of leptin, adiponectin, MMP-3, and the detection of Gleason patterns 4 and 5 at biopsy. A statistically significant association emerged with older age (P = 0.017) and higher PSA values (P = 0.02).

Conclusion:

We did not find any association between BMI, VAI, the plasmatic levels of adiponectin, leptin, and MMP-3 and the detection of Gleason patterns 4 and 5 at prostate biopsy.

Characterization and stratification of prostate lesions based on comprehensive multiparametric MRI using detailed whole-mount histopathology as a reference standard

The purpose of this study was to characterize prostate cancer (PCa) based on multiparametric MR (mpMR) measures derived from MRI, diffusion, spectroscopy, and dynamic contrast-enhanced (DCE) MRI, and to validate mpMRI in detecting PCa and predicting PCa aggressiveness by correlating mpMRI findings with whole-mount histopathology. Seventy-eight men with untreated PCa received 3 T mpMR scans prior to radical prostatectomy. Cancerous regions were outlined, graded, and cancer amount estimated on whole-mount histology. Regions of interest were manually drawn on T₂ -weighted images based on histopathology. Logistic regression was used to identify optimal combinations of parameters for the peripheral zone and transition zone to separate: (i) benign from malignant tissues; (ii) Gleason score (GS) ≤3 + 3 disease from ≥GS3 + 4; and (iii) ≤ GS3 + 4 from ≥GS4 + 3 cancers. The performance of the models was assessed using repeated fourfold cross-validation. Additionally, the performance of the logistic regression models created under the assumption that one or more modality has not been acquired was evaluated. Logistic regression models yielded areas under the curve (AUCs) of 1.0 and 0.99 when separating benign from malignant tissues in the peripheral zone and the transition zone, respectively. Within the peripheral zone, combining choline, maximal enhancement slope, apparent diffusion coefficient (ADC), and citrate measures for separating ≤GS3 + 3 from ≥GS3 + 4 PCa yielded AUC = 0.84. Combining creatine, choline, and washout slope yielded AUC = 0.81 for discriminating ≤GS3 + 4 from ≥GS4 + 3 disease. Within the transition zone, combining washout slope, ADC, and creatine yielded AUC = 0.93 for discriminating ≤GS3 + 3 and ≥GS3 + 4 cancers. When separating ≤GS3 + 4 from ≥GS4 + 3 PCa, combining choline and washout slope yielded AUC = 0.92. MpMRI provides excellent separation between benign tissues and PCa, and across PCa tissues of different aggressiveness. The final models prominently feature spectroscopy and DCE-derived metrics, underlining their value within a comprehensive mpMRI examination.

Communicating risk in active surveillance of localised prostate cancer: a protocol for a qualitative study

INTRODUCTION

One in five men is likely to receive a diagnosis of prostate cancer (PCa) by the age of 85 years. Men diagnosed with low-risk PCa may be eligible for active surveillance (AS) to monitor their cancer to ensure that any changes are discovered and responded to in a timely way. Communication of risk in this context is more complicated than determining a numerical probability of risk, as patients wish to understand the implications of risk on their lives in concrete terms. Our study will examine how risk for PCa is perceived, experienced and communicated by patients using AS with their health professionals, and the implications for treatment and care.

METHODS AND ANALYSIS

This is a proof of concept study, testing out a multimethod, qualitative approach to data collection in the context of PCa for the first time in Australia. It is being conducted from November 2016 to December 2017 in an Australian university hospital urology clinic. Participants are 10 men with a diagnosis of localised PCa, who are using an AS protocol, and 5 health professionals who work with this patient group (eg, urologists and Pca nurses). Data will be collected using observations of patient consultations with health professionals, patient questionnaires and interviews, and interviews with healthcare professionals. Analysis will be conducted in two stages. First, observational data from consultations will be analysed thematically to encapsulate various dimensions of risk classification and consultation dialogue. Second, interview data will be coded to derive meaning in text and analysed thematically. Overarching themes will represent patient and health professional perspectives of risk communication.

ETHICS AND DISSEMINATION

Ethical approval for the study has been granted by Macquarie University Human Research Ethics Committee, approval 5201600638. Knowledge translation will be achieved through publications, reports and conference presentations to patients, families, clinicians and researchers.

Prostate cancer diagnosis using epigenetic biomarkers, 3D high-content imaging and probabilistic cell-by-cell classifiers

Background

Prostate cancer (PCa) management can benefit from novel concepts/biomarkers for reducing the current 20-30% chance of false-negative diagnosis with standard histopathology of biopsied tissue.

Method

We explored the potential of selected epigenetic markers in combination with validated histopathological markers, 3D high-content imaging, cell-by-cell analysis, and probabilistic classification in generating novel detailed maps of biomarker heterogeneity in patient tissues, and PCa diagnosis. We used consecutive biopsies/radical prostatectomies from five patients for building a database of ∼140,000 analyzed cells across all tissue compartments and for model development; and from five patients and the two well-characterized HPrEpiC primary and LNCaP cancer cell types for model validation.

Results

Principal component analysis presented highest covariability for the four biomarkers 4′,6-diamidino-2-phenylindole, 5-methylcytosine, 5-hydroxymethylcytosine, and alpha-methylacyl-CoA racemase in the epithelial tissue compartment. The panel also showed best performance in discriminating between normal and cancer-like cells in prostate tissues with a sensitivity and specificity of 85%, correctly classified 87% of HPrEpiC as healthy and 99% of LNCaP cells as cancer-like, identified a majority of aberrant cells within histopathologically benign tissues at baseline diagnosis of patients that were later diagnosed with adenocarcinoma. Using k-nearest neighbor classifier with cells from an initial patient biopsy, the biomarkers were able to predict cancer stage and grade of prostatic tissue that occurred at later prostatectomy with 79% accuracy.

Conclusion

Our approach showed favorable diagnostic values to identify the portion and pathological category of aberrant cells in a small subset of sampled tissue cells, correlating with the degree of malignancy beyond baseline.

The effect of Rapid Access Prostate Clinics on the outcomes of Gleason 7 prostate cancer: does earlier diagnosis lead to better outcomes?

INTRODUCTION

Rapid Access Prostate Clinics (RAPC) were introduced in Ireland by the National Cancer Control Programme bringing about expedited referral pathways and increased detection rates of prostate cancer. Lower Gleason (G) grade at diagnosis due to RAPC has been previously reported but grade at prostatectomy has not been assessed. The aim of this study was to assess the impact of RAPC on the outcomes of patients with G7 disease on radical prostatectomy (RP).

METHODS

A retrospective analysis was carried out of all RPs performed over a 9-year period (2006-2014). Outcomes for G7 prostatectomies were compared before and after the introduction of the RAPC, with a further sub-analysis of G4 + 3 versus G3 + 4. The primary outcome was biochemical recurrence (BCR). Other outcomes were adjuvant/salvage radiotherapy, extra prostatic extension, positive surgical margins, seminal vesicle involvement and tumour stage.

RESULTS

In total, 240 RPs were performed with 167 cases graded G7 (70 graded G4 + 3 and 97 graded G3 + 4). Since the introduction of RAPC the proportion of G4 + 3 compared to G3 + 4 has increased from 37.9 to 42%. There was no statistical difference in outcomes for G4 + 3 treated before and after the introduction of RAPC. G4 + 3 was associated with higher rates of BCR (24.4 vs. 0%, p < 0.0001, radiotherapy (41.1 vs. 4.8%, p < 0.0001) and worse histological features than G3 + 4.

CONCLUSION

Despite the benefits in diagnosis of prostate cancer brought about by RAPC in Ireland, this has not translated to a lower grade for surgically treated patients. There has been no improvement in outcomes especially for higher grade G4 + 3 disease.

Molecular Profiling to Determine Clonality of Serial Magnetic Resonance Imaging/Ultrasound Fusion Biopsies from Men on Active Surveillance for Low-Risk Prostate Cancer

Purpose: To determine whether MRI/ultrasound (MRI/US) fusion biopsy facilitates longitudinal resampling of the same clonal focus of prostate cancer and to determine whether high-grade cancers can evolve from low-grade clones.Experimental Design: All men on active surveillance who underwent tracking MRI/US fusion biopsy of Gleason 6 prostate cancer, on at least two distinct occasions, between 2012 and 2014 were enrolled. MRI/US fusion was used to track and resample specific cancer foci. IHC for ERG and targeted RNA/DNA next-generation sequencing (NGS) were performed on formalin-fixed paraffin-embedded prostate biopsy specimens to assess clonality.Results: Thirty-one men with median age and PSA of 65 years and 4.6 ng/mL, respectively, were analyzed. The median sampling interval was 12 months (range, 5-35). Of the 26 evaluable men, ERG IHC concordance was found between initial and repeat biopsies in 25 (96%), indicating resampling of the same clonal focus over time. Targeted NGS supported ERG IHC results and identified unique and shared driving mutations, such as IDH1 and SPOP, in paired specimens. Of the nine men (34.6%) who were found to have Gleason ≥7 on repeat biopsy, all displayed temporal ERG concordance. Prioritized genetic alterations were detected in 50% (13/26) of paired samples. Oncogenic mutations were detected in 22% (2/9) of Gleason 6 cancers prior to progression and 44% (4/9) of Gleason ≥7 cancers when progression occurred.Conclusions: Precise tracking of prostate cancer foci via MRI/US fusion biopsy allowed subsequent resampling of the same clonal focus of cancer over time. Further research is needed to clarify the grade progression potential of Gleason 6 prostate cancer. Clin Cancer Res; 23(4); 985-91. ©2016 AACR.

What is the best way not to treat prostate cancer?

INTRODUCTION

Selective treatment approaches for prostate cancer (PCa) are warranted given the highly varied nature of the disease and the consequences associated with definitive therapy.

MATERIALS AND METHODS

We present a stepwise overview of strategies optimized to not treat PCa, ranging from improved screening practices that seek to maximize the yield at initial diagnosis, as well as refinements to clinical risk prediction and the performance of active surveillance.

RESULTS

Improved adherence to screening guidelines offering simplistic, rational practice recommendations are poised to improve the performance of early detection strategies. In addition, measures to improve the quality of PCa screening would include greater integration of novel markers with higher specificity for clinically significant disease, in an effort to stem the tide of over-diagnosis and consequential overtreatment of low-grade tumors. For men diagnosed with PCa, the use of validated, multi-variable risk stratification stands to offer greater certainty in initial management choices: consideration of active surveillance for those with low-risk status, and definitive therapy for men with intermediate and high-risk features. We review the efficacy and nature of active surveillance protocols, and offer a context for refinements that may be anticipated with future study.

CONCLUSIONS

The question of how best to not treat prostate cancer is often more complex than policies of universal treatment, yet is integral to minimize morbidity of over-treatment in patients with low-risk tumors. An array of refined risk stratification instruments, biomarkers, and genomic assays seek to improve the confidence both prior to, and following diagnosis.

Prostate cancer changes in clinical presentation and treatments in two decades: an Italian population-based study

INTRODUCTION

The incidence of prostate cancer is on the rise in many industrialised countries, including Italy, most likely because of the spread of PSA testing. In Italy, prostate cancer mortality has been dropping since 2000, but it is difficult to understand whether PSA testing is the main reason, considering the role of treatment in prognosis. The objectives of this study were: (1) to describe Italian trends of prostate cancer risk categories and corresponding changes in treatment patterns and (2) to interpret changes in survival over time.

METHODS

We made a retrospective observational study using population-based cancer registries. We examined two periods, 1996-1999 and 2005-2007, analysing the distribution of patients among risk groups and treatment changes in those intervals. We estimated 7- and 15-year relative survival with the cohort approach, Ederer II method. We analysed 4635 cases.

RESULTS

There was downward risk migration from the first to the second period. In patients younger than 75 years, there was an increase in radical prostatectomy but not radiotherapy; patients older than 75 years rarely had treatment with radical intent. We noted an improvement of prostate cancer survival in the high-risk group.

CONCLUSION

These findings raise several questions: the possible overtreatment of low-risk patients undergoing radical treatment; the utility of more aggressive treatment for elderly patients with high-risk disease; and the importance of a multidisciplinary clinical approach to ensure multiple and alternative treatment options. The increase in survival, with the decrease in mortality, suggests an effect of radical treatments on prognosis.

Predicting Gleason score using the initial serum total prostate-specific antigen in Black men with symptomatic prostate adenocarcinoma in Nigeria

Background

Men of Black African descent are known to have the highest incidence of prostate cancer. The disease is also more aggressive in this group possibly due to biologically more aggressive tumor or late presentation. Currently, serum prostate-specific antigen (PSA) assay plays a significant role in making the diagnosis of prostate cancer. However, the obtained value of serum PSA may not directly relate with the Gleason score (GS), a measure of tumor aggression in prostate cancer. This study explores the relationship between serum total PSA at presentation (iPSA) and GS.

Patients and methods

The iPSA of patients with histologically confirmed prostate cancer was compared with the obtained GS of the prostate biopsy specimens. The age of the patients at presentation and the prostate volumes were also analyzed with respect to the iPSA and GS. The data were analyzed retrospectively using IBM SPSS Version 20. Pearson correlation was used for numeric variables, whereas Fisher’s exact test was used for categorical variables. Significance was set at P≤0.05.

Results

There were 205 patients from January 2010 to November 2013 who satisfied the inclusion criteria. iPSA as well as age at presentation and prostate volume were not found to significantly correlate with the primary Gleason grade, the secondary Gleason grade, or the GS. However, the presence of distant metastasis was identified to significantly correlate positively with GS.

Conclusion

GS may not be confidently predicted by the iPSA. Higher iPSA does not correlate with higher GS and vice versa.

The Significance of Accurate Determination of Gleason Score for Therapeutic Options and Prognosis of Prostate Cancer

The Gleason score (GS) to date remains one of the most reliable prognostic predictors in prostate cancer (PCa). However, the majority of studies supporting its prognostic relevance were performed prior to its modification by the International Society of Urological Pathology (ISUP) in 2005. Furthermore, the combination of Gleason grading and nuclear/nucleolar subgrading (Helpap score) has been shown to essentially improve grading concordance between biopsy and radical prostatectomy (RP) specimens. This prompted us to investigate the modified GS and combigrading (Gleason/Helpap score) in association with clinicopathological features, biochemical recurrence (BCR), and survival. Core needle biopsies and corresponding RP specimens from 580 patients diagnosed with PCa between 2005 and 2010 were evaluated. According to the modified GS, the comparison between biopsy and RP samples resulted in an upgrading from GS 6 to GS 7a and GS 7b in 65% and 19%, respectively. Combigrading further resulted in an upgrading from low grade (GS 6/2a) to intermediate grade PCa (GS 6/2b) in 11.1% and from intermediate grade (GS 6/2b) to high grade PCa (GS 7b/2b) in 22.6%. Overall, well-differentiated PCa (GS 6/2a) was detected in 2.8% of RP specimens, while intermediate grade (GS 6/2b and GS 7a/2b) and high grade cancers (≥ GS 7b) accounted for 39.5% and 57.4% of cases, respectively. At a mean follow-up of 3.9 years, BCR was observed in 17.6% of patients with intermediate (9.8%) or high grade PCa (30.2%), while PSA relapse did not occur in GS 6/2a PCa. In conclusion, adding nuclear/nucleolar subgrading to the modified GS allowed for a more accurate distinction between low and intermediate grade PCa, therefore offering a valuable tool for the identification of patients eligible for active surveillance (AS).

Automatic classification of prostate cancer Gleason scores from multiparametric magnetic resonance images

Noninvasive, radiological image-based detection and stratification of Gleason patterns can impact clinical outcomes, treatment selection, and the determination of disease status at diagnosis without subjecting patients to surgical biopsies. We present machine learning-based automatic classification of prostate cancer aggressiveness by combining apparent diffusion coefficient (ADC) and T2-weighted (T2-w) MRI-based texture features. Our approach achieved reasonably accurate classification of Gleason scores (GS) 6(3 + 3) vs. ≥7 and 7(3 + 4) vs. 7(4 + 3) despite the presence of highly unbalanced samples by using two different sample augmentation techniques followed by feature selection-based classification. Our method distinguished between GS 6(3 + 3) and ≥7 cancers with 93% accuracy for cancers occurring in both peripheral (PZ) and transition (TZ) zones and 92% for cancers occurring in the PZ alone. Our approach distinguished the GS 7(3 + 4) from GS 7(4 + 3) with 92% accuracy for cancers occurring in both the PZ and TZ and with 93% for cancers occurring in the PZ alone. In comparison, a classifier using only the ADC mean achieved a top accuracy of 58% for distinguishing GS 6(3 + 3) vs. GS ≥7 for cancers occurring in PZ and TZ and 63% for cancers occurring in PZ alone. The same classifier achieved an accuracy of 59% for distinguishing GS 7(3 + 4) from GS 7(4 + 3) occurring in the PZ and TZ and 60% for cancers occurring in PZ alone. Separate analysis of the cancers occurring in TZ alone was not performed owing to the limited number of samples. Our results suggest that texture features derived from ADC and T2-w MRI together with sample augmentation can help to obtain reasonably accurate classification of Gleason patterns.

Increased prostate cancer specific mortality following radical prostatectomy in men presenting with voiding symptoms-A whole of population study

BACKGROUND

Whole of population studies reporting long-term outcomes following radical prostatectomy (RP) are scarce. We aimed to evaluate the long-term outcomes in men with prostate cancer (PC) treated with RP in a whole of population cohort. A secondary objective was to evaluate the influence of mode of presentation on PC specific mortality (PCSM).

METHODS

A prospective database of all cases of RP performed in Victoria, Australia between 1995 and 2000 was established within the Victorian Cancer Registry. Specimen histopathology reports and prostate-specific antigen (PSA) values were obtained by record linkage to pathology laboratories. Mode of presentation was recorded as either PSA screened (PSA testing offered in absence of voiding symptoms) or symptomatic (diagnosis of PC following presentation with voiding symptoms). Multivariate Cox and competing risk regression models were fitted to analyze all-cause mortality, biochemical recurrence, and PCSM.

RESULTS

Between 1995 and 2000, 2,154 men underwent RP in Victoria. During median follow up of 10.2 years (range 0.26-13.5 years), 74 men died from PC. In addition to Gleason score and pathological stage, symptomatic presentation was associated with PCSM. After adjusting for stage and PSA, no difference in PCSM was found between men with Gleason score ≤ 6 and Gleason score 3 + 4 = 7. Men with Gleason score 4 + 3 had significantly greater cumulative incidence of PCSM compared with men with Gleason score 3 + 4.

CONCLUSIONS

Primary Gleason pattern in Gleason 7 PC is an important prognosticator of survival. Our findings suggest that concomitant voiding symptoms should be considered in the work-up and treatment of PC.

Not all gleason pattern 4 prostate cancers are created equal: A study of latent prostatic carcinomas in a cystoprostatectomy and autopsy series

BACKGROUND

The Gleason grading system represents the cornerstone of the management of prostate cancer. Gleason grade 4 (G4) is a heterogeneous set of architectural patterns, each of which may reflect a distinct prognostic value.

METHODS

We determined the prevalence of the various G4 architectural patterns and intraductal carcinoma (IDC) in latent prostate cancer in contemporary Russian (n = 220) and Japanese (n = 100) autopsy prostates and in cystoprostatectomy (CP) specimens (n = 248) collected in Italy. We studied the association of each G4 pattern with extraprostatic extension (EPE) and tumor volume to gain insight into their natural history. Presence of IDC and nine architectural features of Gleason grade 4 and 5 cancer were recorded.

RESULTS

The prevalence of Gleason score ≥ 7 PC was higher in the autopsy series (11%) compared to the CP series (6.5%, P = 0.04). The prevalence of IDC and carcinoma with a cribriform architecture was 2.2% and 3.4% in the autopsy series and 0.8% and 3.6% in the cystoprostatectomy series, respectively. In multivariable analysis, cribriform architecture was significantly associated with increased tumor volume (P < 0.001) and EPE (OR:11.48, 95%CI:2.30-57.16, P = 0.003). IDC was also significantly associated with EPE (OR:10.08, 95%CI:1.58-64.28, P = 0.014). Small fused glands had a strong negative association with EPE in the autopsy series (OR:0.06, 95%CI:0.01-0.58, P = 0.015).

DISCUSSION

Our study revealed that in latent prostate cancer both cribriform architecture and IDC are uniquely associated with poor pathological outcome features. In contrast, Gleason score 7 (3 + 4) cancers with small-fused gland pattern might possibly include some prostate cancers with a more indolent biology.

Should Gleason 6 be labeled as cancer?

PUPOSE OF REVIEW

The review covers arguments for and against removing the label of 'cancer' in Gleason score 6 prostate tumors.

RECENT FINDINGS

While there are a number of factors that determine whether men elect active surveillance, the most powerful predictor remains the Gleason score. Gleason grading remains a robust and powerful predictor of outcome in patients with prostate cancer. A pure Gleason score 6 (GS6) tumor is exceedingly unlikely to cause harm in the near term, and there have been discussions regarding whether the term cancer should still be applied. In this review, we update the largely clinico-pathological arguments that have led to the suggestion to remove the cancer label from GS6 tumors, and we provide counter arguments on the basis of practical matters of needle biopsy sampling, classical histopathology, and molecular biology findings.

SUMMARY

The implications are that by retaining the label of cancer and implementing the recently proposed concept of prognostic groups, with patients harboring GS6 tumors placed into the lowest category, there is still a strong rationale in support of the choice of active surveillance or watchful waiting for most patients with GS6 lesions.

Earlier prostate-specific antigen testing in African American men--Clinical support for the recommendation

BACKGROUND

To determine whether prostate-specific antigen (PSA) testing in African American veterans (AAVs) aged 40 to 54 years is associated with high-risk prostate cancer characteristics compared with AAVs aged 55 to 70 years or white veterans (WVs) aged 40 to 54 years.

METHODS

A total of 231,174 healthy veterans aged 40 to 70 years without clinical evidence of prostate cancer underwent PSA testing between October 1, 2000, and September 30, 2007. Clinicopathologic tumor characteristics were available for 1,044/1,059 AAVs and 1,006/1,971 age-matched WVs diagnosed with prostate cancer after a PSA level>4 ng/ml triggered prostate biopsy. Tumor characteristics of AAVs aged 40 to 54 years were compared with AAVs 55 to 70 years, WVs 40 to 54 years, and WVs 55 to 70 years.

RESULTS

Of PSA-tested veterans aged 40 to 54 years diagnosed with prostate cancer, there were no racial differences in prebiopsy PSA levels, prostate cancer grade, or clinical stage at diagnosis. AAVs aged 40 to 54 years were more likely to have ≥ 3 positive cores (P = 0.0229) and were less likely to be active surveillance candidates (P = 0.0340) compared with similarly aged WVs. AAVs aged 55 to 70 years were more likely to have high-grade (P = 0.0204) and higher clinical stage (P = 0.0195) prostate cancer than AAVs aged 40 to 54 years.

CONCLUSIONS

This large national cohort study suggests that PSA testing at an earlier age for African American men may allow diagnosis of lower risk prostate cancer, potentially reducing disparate outcomes between AAVs and WVs.

The service encounter in radiology: acing the "moments of truth" to achieve patient-centered care

Radiologists are increasingly recognizing their role as direct service providers to patients and seeking to offer an exceptional patient experience as part of high-quality service delivery. Patients' perceptions of service delivery are derived from the chain of numerous individual real-time encounters that occur throughout their visit. These so-called "moments of truth" define the overall experience and form the lasting impression of the given practice in their mind. Providing excellent service can be difficult to achieve in practice given its intangible nature as well as the heterogeneity and unpredictability of the large number of patients, frontline staff, and environmental circumstances that define the patient experience. Thus, broad commitment and team effort among all members of a radiology practice are required. This article explores important areas to be considered by a radiology practice to ensure positive and meaningful patient experiences. Specific ways in which every member within the practice, including schedulers, receptionists, technologists, nurses, and radiologists, can contribute to achieving high-quality patient service are discussed. Examples of patient-oriented language that may be useful in particular scenarios in radiology practice are given. The role of the practice's physical facility, including all aspects of its aesthetics and amenities, as well as of Internet services, in shaping the patient experience is also described. Throughout this work, a proactive approach to promoting a service-oriented organizational culture is provided. By improving the patient experience, these strategies may serve to enhance patients' perceptions of radiology and radiologists.

Biologic differences between peripheral and transition zone prostate cancer

BACKGROUND

Prostate cancer arises in the transition zone (TZ) in approximately 20-25% of cases. Modern biopsy and surveillance protocols, and advances in prostate cancer imaging, have renewed interest in TZ prostate cancers. We compared TZ and PZ prostate cancer to determine if cancer location is independently associated with better outcomes.

METHODS

We evaluated an expanded cohort of 1354 men who underwent radical prostatectomy between 1983 and 2003 with updated long-term clinical follow-up. Regression models were used to compare the volume of high-grade (Gleason 4 or 5) cancer and total cancer volume by location. Uni- and multi-variable logistic regression models tested the associations between cancer location and adverse pathologic features. Multivariable proportional hazard models were fit to examine cancer recurrence.

RESULTS

Patients with TZ cancer presented with higher pre-operative serum PSA values (11.07 vs. 7.86 ng/ml) and larger total cancer volume (7.1 vs. 3.8 cc). Patients with TZ cancer had decreased odds of seminal vesicle invasion (OR 0.08, 95% CI 0.03, 0.21), extra-capsular extension (OR 0.56, 95% CI 0.35, 0.92), and lymphovascular invasion (OR 0.48, 95% CI 0.27, 0.87) in multivariable models. TZ cancers were independently associated with decreased hazard of tumor recurrence (HR 0.62, 95% CI 0.43, 0.90).

CONCLUSIONS

TZ cancer prostate is associated with favorable pathologic features and better recurrence-free survival despite being diagnosed with larger cancers and higher PSA values. Tumor location should be taken into account when stratifying patient risk before and after prostatectomy, particularly with the evolving role of imaging in prostate cancer management.

Global transcriptome analysis of formalin-fixed prostate cancer specimens identifies biomarkers of disease recurrence

Prostate cancer remains the second leading cause of cancer death in American men and there is an unmet need for biomarkers to identify patients with aggressive disease. In an effort to identify biomarkers of recurrence, we performed global RNA sequencing on 106 formalin-fixed, paraffin-embedded prostatectomy samples from 100 patients at three independent sites, defining a 24-gene signature panel. The 24 genes in this panel function in cell-cycle progression, angiogenesis, hypoxia, apoptosis, PI3K signaling, steroid metabolism, translation, chromatin modification, and transcription. Sixteen genes have been associated with cancer, with five specifically associated with prostate cancer (BTG2, IGFBP3, SIRT1, MXI1, and FDPS). Validation was performed on an independent publicly available dataset of 140 patients, where the new signature panel outperformed markers published previously in terms of predicting biochemical recurrence. Our work also identified differences in gene expression between Gleason pattern 4 + 3 and 3 + 4 tumors, including several genes involved in the epithelial-to-mesenchymal transition and developmental pathways. Overall, this study defines a novel biomarker panel that has the potential to improve the clinical management of prostate cancer.

Prostate cancer risk profiles of Asian-American men: disentangling the effects of immigration status and race/ethnicity

PURPOSE

Asian-American men with prostate cancer have been reported to present with higher grade and later stage disease than white American men. However, Asian-American men comprise a heterogeneous population with distinct health outcomes. We compared prostate cancer risk profiles among the diverse racial and ethnic groups in California.

MATERIALS AND METHODS

We used data from the California Cancer Registry on 90,845 nonHispanic white, nonHispanic black and Asian-American men diagnosed with prostate cancer between 2004 and 2010. Patients were categorized into low, intermediate and high risk groups based on clinical stage, Gleason score and prostate specific antigen at diagnosis. Using polytomous logistic regression we estimated adjusted ORs for the association of race/ethnicity and nativity with risk group.

RESULTS

In addition to the nonHispanic black population, 6 Asian-American groups (United States born Chinese, foreign born Chinese, United States born Japanese, foreign born Japanese, foreign born Filipino and foreign born Vietnamese) were more likely to have an unfavorable risk profile compared to nonHispanic white men. The OR for high vs intermediate risk disease ranged from 1.23 (95% CI 1.02-1.49) for United States born Japanese men to 1.45 (95% CI 1.31-1.60) for foreign born Filipino men. These associations appeared to be driven by higher grade and prostate specific antigen rather than by advanced clinical stage at diagnosis.

CONCLUSIONS

In this large, ethnically diverse, population based cohort Asian-American men were more likely to have an unfavorable risk profile at diagnosis. This association varied by racial/ethnic group and nativity, and was not attributable to later stage at diagnosis. This suggests that Asian men may have biological differences that predispose to more severe disease.

Whole-lesion apparent diffusion coefficient metrics as a marker of percentage Gleason 4 component within Gleason 7 prostate cancer at radical prostatectomy

PURPOSE

To retrospectively assess the utility of whole-lesion apparent diffusion coefficient (ADC) metrics in characterizing the Gleason 4 component of Gleason 7 prostate cancer (PCa) at radical prostatectomy.

MATERIALS AND METHODS

Seventy patients underwent phased-array coil 3T-magnetic resonance imaging (MRI) before prostatectomy. A uropathologist mapped locations and Gleason 4 percentage (G4%) of Gleason 7 tumors. Two radiologists independently reviewed ADC maps, aware of tumor locations but not G4%, and placed a volume-of-interest (VOI) on all slices including each lesion on the ADC map to obtain whole-lesion mean ADC and ADC entropy. Entropy reflects textural variation and increases with greater macroscopic heterogeneity. Performance for characterizing Gleason 7 tumors was assessed with mixed-model analysis of variance (ANOVA) and logistic regression.

RESULTS

Among 84 Gleason 7 tumors (G4% 5%-85%, median 30%; 59 Gleason 3+4, 25 Gleason 4+3), ADC entropy was significantly higher in Gleason 4+3 than Gleason 3+4 tumors (R1: 5.27 ± 0.61 vs. 4.62 ± 0.78, P = 0.001; R2: 5.91 ± 0.32 vs. 5.57 ± 0.56, P = 0.004); mean ADC was not significantly different between these groups (R1: 0.90 ± 0.15*10(-3) cm(2) /s vs. 0.98 ± 0.21*10(-3) cm(2) /s, P = 0.075; R2: 1.06 ± 0.19*10(-3) cm(2) /s vs. 1.14 ± 0.16*10(-3) cm(2) /s, P = 0.083). The area under the receiver operating characteristic (ROC) curve (AUC) for differentiating groups was significantly higher with ADC entropy than mean ADC for one observer (R1: 0.74 vs. 0.57, P = 0.027; R2: 0.69 vs. 0.61, P = 0.329). For R1, correlation with G4% was moderate for ADC entropy (r = 0.45) and weak for mean ADC (r = -0.25). For R2, correlation with G4% was moderate for ADC entropy (r = 0.41) and mean ADC (r = -0.32). For both readers, ADC entropy (P = 0.028-0.003), but not mean ADC (P = 0.384-0.854), was a significant independent predictor of G4%.

CONCLUSION

Whole-lesion ADC entropy outperformed mean ADC in characterizing Gleason 7 tumors and may help refine prognosis for this heterogeneous PCa subset.

Gleason grade progression is uncommon

Gleason grade is universally used for pathologic scoring of the differentiation of prostate cancer. However, it is unknown whether prostate tumors arise well differentiated and then progress to less differentiated forms or if Gleason grade is an early and largely unchanging feature. Prostate-specific antigen (PSA) screening has reduced the proportion of tumors diagnosed at advanced stage, which allows assessment of this question on a population level. If Gleason grade progresses as stage does, one would expect a similar reduction in high-grade tumors. We studied 1,207 Physicians' Health Study and Health Professionals Follow-up Study participants diagnosed with prostate cancer from 1982 to 2004 and treated with prostatectomy. We compared the distribution of grade and clinical stage across the pre-PSA and PSA screening eras. We re-reviewed grade using the ISUP 2005 revised criteria. The proportion of advanced stage tumors dropped more than six-fold, from the earliest period (12/1982-1/1993), 19.9% stage ≥ T3, to the latest (5/2000-12/2004), 3% stage T3, none T4. The proportion of Gleason score ≥ 8 decreased substantially less, from 25.3% to 17.6%. A significant interaction between stage and diagnosis date predicting grade (P = 0.04) suggests that the relationship between grade and stage varies by time period. As the dramatic shift in stage since the introduction of PSA screening was accompanied by a more modest shift in Gleason grade, these findings suggest that grade may be established early in tumor pathogenesis. This has implications for the understanding of tumor progression and prognosis, and may help patients diagnosed with lower grade disease feel more comfortable choosing active surveillance.

The PICTURE study -- prostate imaging (multi-parametric MRI and Prostate HistoScanning™) compared to transperineal ultrasound guided biopsy for significant prostate cancer risk evaluation

OBJECTIVE

The primary objective of the PICTURE study is to assess the negative predictive value of multi-parametric MRI (mp-MRI) and Prostate HistoScanning™ (PHS) in ruling-out clinically significant prostate cancer.

PATIENTS AND METHODS

PICTURE is a prospective diagnostic validating cohort study conforming to level 1 evidence. PICTURE will assess the diagnostic performance of multi-parametric Magnetic Resonance Imaging (mp-MRI) and Prostate HistoScanning™ (PHS) ultrasound. PICTURE will involve validating both index tests against a reference test, transperineal Template Prostate Mapping (TPM) biopsies, which can be applied in all men under evaluation. Men will be blinded to the index test results and both index tests will be reported prospectively prior to the biopsies being taken to ensure reporter blinding. Paired analysis of each of the index tests to the reference test will be done at patient level. Those men with an imaging lesion will undergo targeted biopsies to assess the clinical utility of sampling only suspicious areas. The study is powered to assess the negative predictive value of these imaging modalities in ruling-out clinically significant prostate cancer.

DISCUSSION

The PICTURE study aims to assess the performance characteristics of two imaging modalities (mp-MRI and Prostate HistoScanning) for their utility in the prostate cancer pathway. PICTURE aims to identify if either imaging test may be useful for ruling out clinically significant disease in men under investigation, and also to examine if either imaging modality is useful for the detection of disease. Recruitment is underway and expected to complete in 2014.

Histology core-specific evaluation of the European Society of Urogenital Radiology (ESUR) standardised scoring system of multiparametric magnetic resonance imaging (mpMRI) of the prostate

OBJECTIVES

To evaluate the Prostate Imaging Reporting and Data System (PIRADS) in multiparametric magnetic resonance imaging (mpMRI) based on single cores and single-core histology. To calculate positive (PPV) and negative predictive values (NPV) of different modalities of mpMRI.

PATIENTS AND METHODS

We performed MRI-targeted transrectal ultrasound-guided perineal prostate biopsies on 50 patients (mean age 66 years, mean PSA level of 9.9 ng/mL) with suspicion of prostate cancer. The biopsy trajectories of every core taken were documented in three dimensions (3D) in a 3D-prostate model. Every core was evaluated separately for prostate cancer and the performed biopsy trajectories were projected on mpMRI images. PIRADS scores of 1177 cores were then assessed by a histology 'blinded' uro-radiologist in T2-weighted (T2W), dynamic contrast-enhanced (DCE), diffusion-weighted imaging (DWI) and magnetic resonance spectroscopy (MRS).

RESULTS

The PIRADS score was significantly higher in cores positive for cancer than in negative cores. There was a significant correlation between the PIRADS score and histopathology for every modality. Receiver operating characteristic (ROC) analysis showed excellent specificity for T2W (90% peripheral zone/97% transition zone) and DWI (98%/97%) images regardless of the prostate region observed. These numbers decreased for DCE (80%/93%) and MRS (76%/83%). All modalities had NPVs of 99%, if a PIRADS score threshold of 2 (for T2W, DCE, and MRS) or 3 (for DWI) was used. However, PPVs were low.

CONCLUSIONS

Our results show that PIRADS scoring is feasible for clinical routine and allows standardised reporting. PIRADS can be used as a decision-support system for targeting of suspicious lesions. mpMRI has a high NPV for prostate cancer and, thus, might be a valuable tool in the initial diagnostic evaluation.

Primary Gleason pattern in biopsy Gleason score 7 is predictive of adverse histopathological features and biochemical failure following radical prostatectomy

OBJECTIVE

The aim of this study was to analyse whether primary Gleason pattern in biopsy Gleason score (GS) 7 predicted adverse histopathological features and had an impact on the risk of biochemical failure in a consecutive series of patients undergoing radical prostatectomy (RP).

MATERIAL AND METHODS

Between 2006 and 2010, 441 patients with biopsy GS 7 underwent RP at Rigshospitalet, Copenhagen, Denmark. Favourable histopathological features were defined as pT2 margin-negative cancer, RP specimen GS ≤ 3+4 and no lymph-node metastasis. Adverse histopathological features were defined as advanced pT3/4 cancer or pT2 margin-positive cancer and/or RP specimen GS ≥ 4+3 and/or positive lymph nodes. Biochemical failure was defined as the first prostate-specific antigen (PSA) ≥ 0.2 ng/ml.

RESULTS

A total of 344 patients (78.0%) had GS 3+4 in biopsies, while 97 patients (22.0%) had GS 4+3. No difference in age, PSA, percentage of biopsies with cancer, clinical tumour stage or volume on transrectal ultrasonography was found. Primary Gleason pattern 4 was associated with worse pathological stage (p = 0.049). On multivariate analysis, primary Gleason pattern 4 (p < 0.0001), cT stage (p = 0.024), PSA (p < 0.0001) and age (p = 0.009) predicted adverse histopathological features. In univariate analysis, Gleason score 3+4 had a significantly lower biochemical failure rate compared with Gleason score 4+3 (p = 0.0035). PSA (p < 0.0001), primary Gleason pattern 4 (p = 0.001) and percentage of biopsies with cancer (p = 0.02) were independently associated with risk of biochemical failure.

CONCLUSIONS

In biopsies with GS 7, a primary Gleason pattern 4 was associated with significantly elevated risk of adverse histopathological features and biochemical failure compared to pattern 3 in patients undergoing RP. This study underlines the heterogeneity of biopsy GS 7.